1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 ** PARISC 1.1 Dynamic DMA mapping support. 4 ** This implementation is for PA-RISC platforms that do not support 5 ** I/O TLBs (aka DMA address translation hardware). 6 ** See Documentation/core-api/dma-api-howto.rst for interface definitions. 7 ** 8 ** (c) Copyright 1999,2000 Hewlett-Packard Company 9 ** (c) Copyright 2000 Grant Grundler 10 ** (c) Copyright 2000 Philipp Rumpf <prumpf@tux.org> 11 ** (c) Copyright 2000 John Marvin 12 ** 13 ** "leveraged" from 2.3.47: arch/ia64/kernel/pci-dma.c. 14 ** (I assume it's from David Mosberger-Tang but there was no Copyright) 15 ** 16 ** AFAIK, all PA7100LC and PA7300LC platforms can use this code. 17 ** 18 ** - ggg 19 */ 20 21 #include <linux/init.h> 22 #include <linux/gfp.h> 23 #include <linux/mm.h> 24 #include <linux/proc_fs.h> 25 #include <linux/seq_file.h> 26 #include <linux/string.h> 27 #include <linux/types.h> 28 #include <linux/dma-direct.h> 29 #include <linux/dma-map-ops.h> 30 31 #include <asm/cacheflush.h> 32 #include <asm/dma.h> /* for DMA_CHUNK_SIZE */ 33 #include <asm/io.h> 34 #include <asm/page.h> /* get_order */ 35 #include <linux/uaccess.h> 36 #include <asm/tlbflush.h> /* for purge_tlb_*() macros */ 37 38 static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL; 39 static unsigned long pcxl_used_bytes __read_mostly; 40 static unsigned long pcxl_used_pages __read_mostly; 41 42 unsigned long pcxl_dma_start __ro_after_init; /* pcxl dma mapping area start */ 43 static DEFINE_SPINLOCK(pcxl_res_lock); 44 static char *pcxl_res_map; 45 static int pcxl_res_hint; 46 static int pcxl_res_size; 47 48 #ifdef DEBUG_PCXL_RESOURCE 49 #define DBG_RES(x...) printk(x) 50 #else 51 #define DBG_RES(x...) 52 #endif 53 54 55 /* 56 ** Dump a hex representation of the resource map. 57 */ 58 59 #ifdef DUMP_RESMAP 60 static 61 void dump_resmap(void) 62 { 63 u_long *res_ptr = (unsigned long *)pcxl_res_map; 64 u_long i = 0; 65 66 printk("res_map: "); 67 for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr) 68 printk("%08lx ", *res_ptr); 69 70 printk("\n"); 71 } 72 #else 73 static inline void dump_resmap(void) {;} 74 #endif 75 76 static inline int map_pte_uncached(pte_t * pte, 77 unsigned long vaddr, 78 unsigned long size, unsigned long *paddr_ptr) 79 { 80 unsigned long end; 81 unsigned long orig_vaddr = vaddr; 82 83 vaddr &= ~PMD_MASK; 84 end = vaddr + size; 85 if (end > PMD_SIZE) 86 end = PMD_SIZE; 87 do { 88 unsigned long flags; 89 90 if (!pte_none(*pte)) 91 printk(KERN_ERR "map_pte_uncached: page already exists\n"); 92 purge_tlb_start(flags); 93 set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC)); 94 pdtlb(SR_KERNEL, orig_vaddr); 95 purge_tlb_end(flags); 96 vaddr += PAGE_SIZE; 97 orig_vaddr += PAGE_SIZE; 98 (*paddr_ptr) += PAGE_SIZE; 99 pte++; 100 } while (vaddr < end); 101 return 0; 102 } 103 104 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr, 105 unsigned long size, unsigned long *paddr_ptr) 106 { 107 unsigned long end; 108 unsigned long orig_vaddr = vaddr; 109 110 vaddr &= ~PGDIR_MASK; 111 end = vaddr + size; 112 if (end > PGDIR_SIZE) 113 end = PGDIR_SIZE; 114 do { 115 pte_t * pte = pte_alloc_kernel(pmd, vaddr); 116 if (!pte) 117 return -ENOMEM; 118 if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr)) 119 return -ENOMEM; 120 vaddr = (vaddr + PMD_SIZE) & PMD_MASK; 121 orig_vaddr += PMD_SIZE; 122 pmd++; 123 } while (vaddr < end); 124 return 0; 125 } 126 127 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size, 128 unsigned long paddr) 129 { 130 pgd_t * dir; 131 unsigned long end = vaddr + size; 132 133 dir = pgd_offset_k(vaddr); 134 do { 135 p4d_t *p4d; 136 pud_t *pud; 137 pmd_t *pmd; 138 139 p4d = p4d_offset(dir, vaddr); 140 pud = pud_offset(p4d, vaddr); 141 pmd = pmd_alloc(NULL, pud, vaddr); 142 143 if (!pmd) 144 return -ENOMEM; 145 if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr)) 146 return -ENOMEM; 147 vaddr = vaddr + PGDIR_SIZE; 148 dir++; 149 } while (vaddr && (vaddr < end)); 150 return 0; 151 } 152 153 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr, 154 unsigned long size) 155 { 156 pte_t * pte; 157 unsigned long end; 158 unsigned long orig_vaddr = vaddr; 159 160 if (pmd_none(*pmd)) 161 return; 162 if (pmd_bad(*pmd)) { 163 pmd_ERROR(*pmd); 164 pmd_clear(pmd); 165 return; 166 } 167 pte = pte_offset_kernel(pmd, vaddr); 168 vaddr &= ~PMD_MASK; 169 end = vaddr + size; 170 if (end > PMD_SIZE) 171 end = PMD_SIZE; 172 do { 173 unsigned long flags; 174 pte_t page = *pte; 175 176 pte_clear(&init_mm, vaddr, pte); 177 purge_tlb_start(flags); 178 pdtlb(SR_KERNEL, orig_vaddr); 179 purge_tlb_end(flags); 180 vaddr += PAGE_SIZE; 181 orig_vaddr += PAGE_SIZE; 182 pte++; 183 if (pte_none(page) || pte_present(page)) 184 continue; 185 printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n"); 186 } while (vaddr < end); 187 } 188 189 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr, 190 unsigned long size) 191 { 192 pmd_t * pmd; 193 unsigned long end; 194 unsigned long orig_vaddr = vaddr; 195 196 if (pgd_none(*dir)) 197 return; 198 if (pgd_bad(*dir)) { 199 pgd_ERROR(*dir); 200 pgd_clear(dir); 201 return; 202 } 203 pmd = pmd_offset(pud_offset(p4d_offset(dir, vaddr), vaddr), vaddr); 204 vaddr &= ~PGDIR_MASK; 205 end = vaddr + size; 206 if (end > PGDIR_SIZE) 207 end = PGDIR_SIZE; 208 do { 209 unmap_uncached_pte(pmd, orig_vaddr, end - vaddr); 210 vaddr = (vaddr + PMD_SIZE) & PMD_MASK; 211 orig_vaddr += PMD_SIZE; 212 pmd++; 213 } while (vaddr < end); 214 } 215 216 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size) 217 { 218 pgd_t * dir; 219 unsigned long end = vaddr + size; 220 221 dir = pgd_offset_k(vaddr); 222 do { 223 unmap_uncached_pmd(dir, vaddr, end - vaddr); 224 vaddr = vaddr + PGDIR_SIZE; 225 dir++; 226 } while (vaddr && (vaddr < end)); 227 } 228 229 #define PCXL_SEARCH_LOOP(idx, mask, size) \ 230 for(; res_ptr < res_end; ++res_ptr) \ 231 { \ 232 if(0 == ((*res_ptr) & mask)) { \ 233 *res_ptr |= mask; \ 234 idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \ 235 pcxl_res_hint = idx + (size >> 3); \ 236 goto resource_found; \ 237 } \ 238 } 239 240 #define PCXL_FIND_FREE_MAPPING(idx, mask, size) { \ 241 u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \ 242 u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \ 243 PCXL_SEARCH_LOOP(idx, mask, size); \ 244 res_ptr = (u##size *)&pcxl_res_map[0]; \ 245 PCXL_SEARCH_LOOP(idx, mask, size); \ 246 } 247 248 static unsigned long 249 pcxl_alloc_range(size_t size) 250 { 251 int res_idx; 252 u_long mask, flags; 253 unsigned int pages_needed = size >> PAGE_SHIFT; 254 255 mask = (u_long) -1L; 256 mask >>= BITS_PER_LONG - pages_needed; 257 258 DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n", 259 size, pages_needed, mask); 260 261 spin_lock_irqsave(&pcxl_res_lock, flags); 262 263 if(pages_needed <= 8) { 264 PCXL_FIND_FREE_MAPPING(res_idx, mask, 8); 265 } else if(pages_needed <= 16) { 266 PCXL_FIND_FREE_MAPPING(res_idx, mask, 16); 267 } else if(pages_needed <= 32) { 268 PCXL_FIND_FREE_MAPPING(res_idx, mask, 32); 269 } else { 270 panic("%s: pcxl_alloc_range() Too many pages to map.\n", 271 __FILE__); 272 } 273 274 dump_resmap(); 275 panic("%s: pcxl_alloc_range() out of dma mapping resources\n", 276 __FILE__); 277 278 resource_found: 279 280 DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n", 281 res_idx, mask, pcxl_res_hint); 282 283 pcxl_used_pages += pages_needed; 284 pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1); 285 286 spin_unlock_irqrestore(&pcxl_res_lock, flags); 287 288 dump_resmap(); 289 290 /* 291 ** return the corresponding vaddr in the pcxl dma map 292 */ 293 return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3))); 294 } 295 296 #define PCXL_FREE_MAPPINGS(idx, m, size) \ 297 u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \ 298 /* BUG_ON((*res_ptr & m) != m); */ \ 299 *res_ptr &= ~m; 300 301 /* 302 ** clear bits in the pcxl resource map 303 */ 304 static void 305 pcxl_free_range(unsigned long vaddr, size_t size) 306 { 307 u_long mask, flags; 308 unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3); 309 unsigned int pages_mapped = size >> PAGE_SHIFT; 310 311 mask = (u_long) -1L; 312 mask >>= BITS_PER_LONG - pages_mapped; 313 314 DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n", 315 res_idx, size, pages_mapped, mask); 316 317 spin_lock_irqsave(&pcxl_res_lock, flags); 318 319 if(pages_mapped <= 8) { 320 PCXL_FREE_MAPPINGS(res_idx, mask, 8); 321 } else if(pages_mapped <= 16) { 322 PCXL_FREE_MAPPINGS(res_idx, mask, 16); 323 } else if(pages_mapped <= 32) { 324 PCXL_FREE_MAPPINGS(res_idx, mask, 32); 325 } else { 326 panic("%s: pcxl_free_range() Too many pages to unmap.\n", 327 __FILE__); 328 } 329 330 pcxl_used_pages -= (pages_mapped ? pages_mapped : 1); 331 pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1); 332 333 spin_unlock_irqrestore(&pcxl_res_lock, flags); 334 335 dump_resmap(); 336 } 337 338 static int __maybe_unused proc_pcxl_dma_show(struct seq_file *m, void *v) 339 { 340 #if 0 341 u_long i = 0; 342 unsigned long *res_ptr = (u_long *)pcxl_res_map; 343 #endif 344 unsigned long total_pages = pcxl_res_size << 3; /* 8 bits per byte */ 345 346 seq_printf(m, "\nDMA Mapping Area size : %d bytes (%ld pages)\n", 347 PCXL_DMA_MAP_SIZE, total_pages); 348 349 seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size); 350 351 seq_puts(m, " total: free: used: % used:\n"); 352 seq_printf(m, "blocks %8d %8ld %8ld %8ld%%\n", pcxl_res_size, 353 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes, 354 (pcxl_used_bytes * 100) / pcxl_res_size); 355 356 seq_printf(m, "pages %8ld %8ld %8ld %8ld%%\n", total_pages, 357 total_pages - pcxl_used_pages, pcxl_used_pages, 358 (pcxl_used_pages * 100 / total_pages)); 359 360 #if 0 361 seq_puts(m, "\nResource bitmap:"); 362 363 for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) { 364 if ((i & 7) == 0) 365 seq_puts(m,"\n "); 366 seq_printf(m, "%s %08lx", buf, *res_ptr); 367 } 368 #endif 369 seq_putc(m, '\n'); 370 return 0; 371 } 372 373 static int __init 374 pcxl_dma_init(void) 375 { 376 if (pcxl_dma_start == 0) 377 return 0; 378 379 pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3); 380 pcxl_res_hint = 0; 381 pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL, 382 get_order(pcxl_res_size)); 383 memset(pcxl_res_map, 0, pcxl_res_size); 384 proc_gsc_root = proc_mkdir("bus/gsc", NULL); 385 if (!proc_gsc_root) 386 printk(KERN_WARNING 387 "pcxl_dma_init: Unable to create gsc /proc dir entry\n"); 388 else { 389 struct proc_dir_entry* ent; 390 ent = proc_create_single("pcxl_dma", 0, proc_gsc_root, 391 proc_pcxl_dma_show); 392 if (!ent) 393 printk(KERN_WARNING 394 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n"); 395 } 396 return 0; 397 } 398 399 __initcall(pcxl_dma_init); 400 401 void *arch_dma_alloc(struct device *dev, size_t size, 402 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) 403 { 404 unsigned long vaddr; 405 unsigned long paddr; 406 int order; 407 408 if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl) 409 return NULL; 410 411 order = get_order(size); 412 size = 1 << (order + PAGE_SHIFT); 413 vaddr = pcxl_alloc_range(size); 414 paddr = __get_free_pages(gfp | __GFP_ZERO, order); 415 flush_kernel_dcache_range(paddr, size); 416 paddr = __pa(paddr); 417 map_uncached_pages(vaddr, size, paddr); 418 *dma_handle = (dma_addr_t) paddr; 419 420 return (void *)vaddr; 421 } 422 423 void arch_dma_free(struct device *dev, size_t size, void *vaddr, 424 dma_addr_t dma_handle, unsigned long attrs) 425 { 426 int order = get_order(size); 427 428 WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 && 429 boot_cpu_data.cpu_type != pcxl); 430 431 size = 1 << (order + PAGE_SHIFT); 432 unmap_uncached_pages((unsigned long)vaddr, size); 433 pcxl_free_range((unsigned long)vaddr, size); 434 435 free_pages((unsigned long)__va(dma_handle), order); 436 } 437 438 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, 439 enum dma_data_direction dir) 440 { 441 /* 442 * fdc: The data cache line is written back to memory, if and only if 443 * it is dirty, and then invalidated from the data cache. 444 */ 445 flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size); 446 } 447 448 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, 449 enum dma_data_direction dir) 450 { 451 unsigned long addr = (unsigned long) phys_to_virt(paddr); 452 453 switch (dir) { 454 case DMA_TO_DEVICE: 455 case DMA_BIDIRECTIONAL: 456 flush_kernel_dcache_range(addr, size); 457 return; 458 case DMA_FROM_DEVICE: 459 purge_kernel_dcache_range_asm(addr, addr + size); 460 return; 461 default: 462 BUG(); 463 } 464 } 465